Quantum phase retrieval of a Rydberg wave packet using a half-cycle pulse

A terahertz half-cycle pulse was used to retrieve information stored as quantum phase in an $N$-state Rydberg atom data register. The register was prepared as a wave packet with one state phase-reversed from the others (the "marked bit"). A half-cycle pulse then drove a significant portion of the electron probability into the flipped state via multimode interference.Comment: accepted by PR

Implementation of quantum search algorithm using classical Fourier optics

We report on an experiment on Grover's quantum search algorithm showing that {\em classical waves} can search a $N$-item database as efficiently as quantum mechanics can. The transverse beam profile of a short laser pulse is processed iteratively as the pulse bounces back and forth between two mirrors. We directly observe the sought item being found in $\sim\sqrt{N}$ iterations, in the form of a growing intensity peak on this profile. Although the lack of quantum entanglement limits the {\em size} of our database, our results show that entanglement is neither necessary for the algorithm itself, nor for its efficiency.Comment: 4 pages, 3 figures; minor revisions plus extra referenc

Medication education program for Indian children with asthma: A feasibility study

Objective: It is postulated that children with asthma who receive an interactive, comprehensive,  culturally relevant education program would improve their asthma knowledge (AK), asthma control, and adherence compared with children receiving usual care. The aim of this study was to develop, implement, and evaluate the efficacy of a culturally relevant asthma education intervention for children with asthma and their parents in India.Methods: Children with asthma (7.12 years) and their parents were recruited from an outpatient clinic in a Chest Diseases Hospital in New Delhi, and were randomly assigned to either an intervention or usual care group. At baseline, outcome data collected included pediatric asthma caregiver quality of life (PACQL, primary outcome), AK, asthma control, adherence, inhaler technique, action plan ownership, and goal achievement. These data were collected again at 1 and 6 months after baseline. Outcomes were compared within and between groups using ANOVA techniques.Results: Forty parent.child pairs were recruited. Of these, 24 pairs of children with asthma and their parents received the educational intervention. The PACQL significantly improved from baseline to 6 months in the intervention (5.87 } 0.94.7.00 } 0.03) versus the usual care group (5.90 } 0.52.6.34 } 0.56) (P < 0.001). Other outcomes such as the parentsf and childfs AK, childfs asthma control and inhaler technique were significantly improved in the intervention group across the study. All the participants possessed a written asthma action plan at the end of the intervention. Eighty.five goals were set by children with asthma across all the visits and were achieved by completion.Conclusion: An asthma educator delivered interactive program simultaneously involving children with asthma and their parents, improved quality of life, empowered and promoted better self.management skills.Key words: Asthma education, asthma knowledge, asthma usual care, caregiver quality of life, childhood asthma, hospital.based program, program evaluatio

Conceptual design study for heat exhaust management in the ARC fusion pilot plant

The ARC pilot plant conceptual design study has been extended beyond its initial scope [B. N. Sorbom et al., FED 100 (2015) 378] to explore options for managing ~525 MW of fusion power generated in a compact, high field (B_0 = 9.2 T) tokamak that is approximately the size of JET (R_0 = 3.3 m). Taking advantage of ARC's novel design - demountable high temperature superconductor toroidal field (TF) magnets, poloidal magnetic field coils located inside the TF, and vacuum vessel (VV) immersed in molten salt FLiBe blanket - this follow-on study has identified innovative and potentially robust power exhaust management solutions.Comment: Accepted by Fusion Engineering and Desig

Fetching marked items from an unsorted database in NMR ensemble computing

Searching a marked item or several marked items from an unsorted database is a very difficult mathematical problem. Using classical computer, it requires $O(N=2^n)$ steps to find the target. Using a quantum computer, Grover's algorithm uses $O(\sqrt{N=2^n})$ steps. In NMR ensemble computing, Brushweiler's algorithm uses $\log N$ steps. In this Letter, we propose an algorithm that fetches marked items in an unsorted database directly. It requires only a single query. It can find a single marked item or multiple number of items.Comment: 4 pages and 1 figur

Quantum heuristic algorithm for traveling salesman problem

We propose a quantum heuristic algorithm to solve a traveling salesman problem by generalizing Grover search. Sufficient conditions are derived to greatly enhance the probability of finding the tours with extremal costs, reaching almost to unity and they are shown characterized by statistical properties of tour costs. In particular for a Gaussian distribution of the tours along the cost we show that the quantum algorithm exhibits the quadratic speedup of its classical counterpart, similarly to Grover search.Comment: Published versio

Energy gaps in quantum first-order mean-field-like transitions: The problems that quantum annealing cannot solve

We study first-order quantum phase transitions in models where the mean-field traitment is exact, and the exponentially fast closure of the energy gap with the system size at the transition. We consider exactly solvable ferromagnetic models, and show that they reduce to the Grover problem in a particular limit. We compute the coefficient in the exponential closure of the gap using an instantonic approach, and discuss the (dire) consequences for quantum annealing.Comment: 6 pages, 3 figure

Expression of factor V by resident macrophages boosts host defense in the peritoneal cavity

Macrophages resident in different organs express distinct genes, but understanding how this diversity fits into tissue-specific features is limited. Here, we show that selective expression of coagulation factor V (FV) by resident peritoneal macrophages in mice promotes bacterial clearance in the peritoneal cavity and serves to facilitate the well-known but poorly understood macrophage disappearance reaction. Intravital imaging revealed that resident macrophages were nonadherent in peritoneal fluid during homeostasis. Bacterial entry into the peritoneum acutely induced macrophage adherence and associated bacterial phagocytosis. However, optimal control of bacterial expansion in the peritoneum also required expression of FV by the macrophages to form local clots that effectively brought macrophages and bacteria in proximity and out of the fluid phase. Thus, acute cellular adhesion and resident macrophage-induced coagulation operate independently and cooperatively to meet the challenges of a unique, open tissue environment. These events collectively account for the macrophage disappearance reaction in the peritoneal cavity

Note and Comment

Epithetical Jurisprudence and the Annexation of Fixtures - If we begin with all the facts of a controversy and proceed inductively to determine the rights of the parties litigant, we thus arrive at a jurisprudence of rights, whereas, if we reason deductively from a rule, a definition, or a maxim of law to its application in the facts of our case, we can at best attain only a jurisprudence of rules, which has been so aptly characterized as an epithetical jurisprudence. The subject of fixtures is one in which we have great difficulty in applying the inductive method because the courts have been slower in approaching the subject scientifically in this field of the law than in others

Efficient quantum algorithms for simulating sparse Hamiltonians

We present an efficient quantum algorithm for simulating the evolution of a sparse Hamiltonian H for a given time t in terms of a procedure for computing the matrix entries of H. In particular, when H acts on n qubits, has at most a constant number of nonzero entries in each row/column, and |H| is bounded by a constant, we may select any positive integer $k$ such that the simulation requires O((\log^*n)t^{1+1/2k}) accesses to matrix entries of H. We show that the temporal scaling cannot be significantly improved beyond this, because sublinear time scaling is not possible.Comment: 9 pages, 2 figures, substantial revision